Waterproof concrete burial vault and method of construction

ABSTRACT

A waterproof concrete burial vault, cast in situ by using inner and outer plastic forms that remain in place. The inner plastic form is watertight and defines at least one casket receiving chamber, a sheet of plastic being secured in a watertight manner to the inner form to completely seal a casket placed within said chamber. The vault features a tube that extends vertically from the bottom to the top thereof, which relieves underground liquid pressure beneath the vault.

United States Patent [72] Inventor Donald A. ,lalbert 612 E. 4th 51.,Blrtlesville, Okla. 74003 [21] Appl. No 828,190 [22] Filed May 27, 1969145] Patented Aug. 3, 197] [S4] WATERPROOF CONCRETE BURIAL VAULT ANDMETHOD OF CONSTRUCTION 19 Claims, 17 Drawing Figs.

{52] US. Cl 52/137, 52/21, 52/169, 52/742 [51 I Int. Cl 1304b 13/00,E02d 31/02 [50] Field of Search 52/128 142, 426, 741-743, 169, 687, 688,19--21; 106/96; 25/130 B; 264/35; 138/174 {56] References Cited UNITEDSTATES PATENTS 1,004,273 9/1911 Johnson 52/139 1,033,733 7/1912 Raddatz52/139 1,034,185 7/1912 Armstrong 52/142 Primaly Examinr-Frank L. AbbottAssistant Examiner-James L. Ridgilll, .lr. Attorney-Bacon & ThomasABSTRACT: A waterproof concrete burial vault, cast in situ by usinginner and outer plastic forms that remain in place. The inner plasticform is watertight and defines at least one casket receiving chamber, asheet of plastic being secured in a watertight manner to the inner formto completely seal a casket placed within said chamber. The vaultfeatures a tube that extends vertically from the bottom to the topthereof, which relieves underground liquid pressure beneath the vault.

WATERPROOF CONCRETE BURIAL VAULT AND METHOD OF CONSTRUCTION BACKGROUNDOF THE INVENTION 1. Field of the Invention This invention relatesgenerally to burial vaults, and more particularly to a waterproof burialvault and the method for constructing the same in situ.

2. Description of the Prior Art It is a common practice to place acasket within an underground burial vault, the vault serving primarilyto protect the casket and keep it dry. There have been numerousconstructions proposed for such burial vaults, including the use ofinvolved composite constructions utilizing many layers of differentmaterials in an effort to achieve a watertight vault. Usually suchvaults are very heavy and are constructed in a factory far removed fromthe cemetery, and hence considerable cost in transportation,installation equipment and labor must be entailed to place them in aparticular grave site.

There is need for a burial vault that can be easily and economicallyconstructed at the grave site, whereby cost can be held to a minimum,and which positively seals a casket placed therein from the entry ofground water or other fluids. The present invention satisfies that need.

A problem with burial vaults where ground waters are abundant has beenthat such waters frequently accumulate beneath the vault, generatingpressures that can shift the vaults position and cause resultant damageto the grave site. The present invention includes means for alleviatingthis problem, and thus contributes to reduced cemetery upkeep costs andpeace of mind to the concerned relatives and friends of a deceased.

SUMMARY OF THE INVENTION In the present invention the burial vault isconstructed in situ from concrete, the first step after digging of thegrave being to place therein spaced, concentrically disposed inner andouter forms of plastic. Concrete mix containing a suitable waterproofingcompound is then poured into the form and allowed to set, after whichthe vault is ready for use.

The plastic forms remain in the vault, and in addition to molding theconcrete serve to provide a vault lining for use in making each burialcompartment watertight. A vault constructed according to the inventioncan be designed to accommodate a single casket, or a plurality ofcaskets. When the vault is for a single casket, the casket is firstlowered into place and then a plastic plate is sealed to the upper edgesof the inner form to completely seal off the casket compartment orchamber. A concrete slab cover is then secured to the upper end of thevault, to complete the burial.

In one multiple casket version of the invention the vault contains aplurality of casket compartments, one above the other. After a casket isplaced in the lowest compartment, a braced plastic plate is installed toseal that compartment, the plate serving as a floor to support the nextcasket. By the concept of the invention whereby each compartment istotally sealed after a casket has been placed therein, the placing ofseveral caskets one above the other in the same vault is rendered bothtotally safe and acceptable to the sensitivities of those burying adeceased. The multiple casket vault of the invention is especiallyuseful to bury several members of a fami- 1y, requiring but a singlecemetery grave site to do so.

In another multiple casket vault constructed according to the invention,the caskets are placed vertically into separate vertically disposedcompartments or chambers, each compartment being sealed by a plasticplate after use and being closed by an individual concrete slab cover.

To relieve any water pressure that might accumulate therebeneath, atleast one pressure relief tube is made a part of the vault and extendsvertically over the height thereof. Preferably two such relief tubes areused, one at each end of the vault, and said tubes function to preventany pressure buildup beneath the vault.

It is an object of the present invention to provide a burial vaulthaving a completely leakproof burial chamber.

Another object is to provide a method for constructing a watertightconcrete burial vault in situ :at the grave site.

A further object is to provide form structure for construct ing aconcrete burial vault, which forms remain in place and serve to made thevault watertight.

Yet another object is to provide a burial vault equipped with means torelieve the pressure of underground water that accumulates therebeneath.

Other objects and many of the attendant advantages of the presentinvention will be readily apparent from the following Description of thePreferred Embodiments, when taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of themultichamber horizontal vault of the present invention, with the coversections in place;

FIG. 2 is a transverse vertical sectional view taken on the line 2-2 ofFIG. 1, showing in particular the construction of the inner and outerplastic forms;

FIG. 3 is a longitudinal vertical sectional view taken on the line 3-3of FIG. 1, showing in particular the arrangement of the pressure relieftubes and the construction of the reinforced plastic sheets;

FIG. 4 is an enlarged staggered horizontal fragmentary sectional view,taken on the line 4-4 of FIG. 3;

FIG. 5 is an enlarged fragmentary vertical sectional view taken on theline 5-5 of FIG. 1, showing in particular the vault seal arrangement;

FIG. 6 is an enlarged fragmentary vertical sectional view taken on theline 6-6 of FIG. l, showing the seal between sections of the cover;

FIG. '7 is an enlarged fragmentary vertical sectional view taken on theline 7-7 of FIG. 4, showing the construction of one of the spacers;

FIG. 8 is an enlarged fragmentary vertical sectional view taken on theline 8-8 of FIG. 2, showing in detail one of the reinforced plasticsheets;

FIG. 9 is an enlarged fragmentary vertical sectional view taken on theline 9-9 of FIG. 4;

FIG. 10 is an enlarged fragmentary vertical sectional view taken on theline 10-10 of FIG. 4;

FIG. 11 is an enlarged fragmentary vertical sectional view taken on theline 11-11 in FIG. 4;

FIG. 12 is a top plan view of a single casket vault constructedaccording to the invention;

FIG. 13 is a vertical sectional view taken on the line 13-13 in FIG. 12;

FIG. 14 is a transverse vertical sectional view taken on the line 14-14in FIG. 12;

FIG. 15 is an enlarged vertical sectional view taken on the line 15-15in FIG. 12, showing how the bolts securing the vault lid are sealed;

FIG. 16 is a top plan view, partially broken away, ofa multiple verticalburial vault constructed according to the invention, wherein thepressure relief tube is secured to the exterior of the outer plasticmold; and

FIG. 17 is a vertical sectional view through the vault of FIG. 16.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1l1 ofthe drawings, there is shown therein at 2 a multiple-casket horizontalvault constructed according to the invention. The vault 2 is constructedin situ within a grave 4 dug in the earth 6, and includes a rectangularboxlike concrete body 8 having an inner plastic form It) and an outerplastic form 12 thereon, the upper end of the vault being closed by amiddle concrete slab lid section 114 and two end lid sections 116 and18, respectively.

The inner and outer forms 10 and 112 are made of polyvinylchloride orsome other suitable plastic, and after serving to mold the concrete asit is poured remain in position on the finished vault body 8 to helprender watertight the casket chambers within the vault. The vault 2contains three casket chambers, a lower chamber 20, a middle chamber 22and an upper chamber 24, it being understood that a vault with more orless chambers than the three shown can also be constructed according tothe invention.

The inner form includes a rectangular bottom plate 26 having anupstanding flange 28 on the periphery thereof, which flange istelescopically received within the lower end of a rectangular lower formsection 30 having planar end walls 32 and 34 and planar side walls 36and 38, respectively. In order to connect the flange 28 to the lowerform section 30, and to made a watertight structure, the entireperiphery of the flange 28 is. secured by chemical fusion, or welding,to the walls of the section 30, as indicated at 40 in FIG. 10. Inaddition, spaced screws 42 are threaded through the flange 28 and thewalls of the section 30. The screws 42 are optional and can be omittedif desired, but if utilized should project substantially beyond thewalls of the lower section 30 so that they serve a anchors in theconcrete body 8.

Received on the lower form section 30 is a middle form section 44,comprising end walls 46 and 48 and side walls 50 and 52, respectively,the upper ends of said walls being planar. The end walls 46 and 48 arespaced apart the same distance as the end walls 32 and 34, and havedownwardly extending flanges 54 on the inner lower edges thereof thatare received within the lower. section 30, the upper surfaces of theflanges 54 defining shoulders 56 that extend at a right angle to the endwalls 46 and 48.

The sidewalls 50 and 52 of the middle form section 44 are spaced furtherapart than the sidewalls 36 and 38, and have in wardly extending rims 58on the lower edges thereof that project perpendicularly from theirassociated sidewalls. The uppersurfaces of the rims 58 define shoulders60, and said rims have downwardly extending flanges 62 thereon that arereceived within the lower section 30 and which are integral with theflanges 54. The flanges 54 and 62 are welded to the inner upper edges ofthe walls of the lower form section 30, as shown at 64 in FIG. 9,whereby a watertight connection is made. In addition, optional screws 66corresponding to the screws 42 also serve to secure togetherthe middleand lower inner form sections 44 and 30.

Received on the middle fonn section 44 is an upper form section 68,comprising end walls 70 and 72 connected by sidewalls 74 and 76, theupperends of all of said walls being planar. The end walls 70 and 72 arespaced apart the same distance as the walls 46 and 48, and havedownwardly directed flanges 78 on the lower edges thereof that defineshoulders 80.

The side walls 74 and 76 are spaced apart further than the wall 50 and52, and have inwardly directed rims 82 thereon that terminate indownwardly directed flange 84, and which define shoulders 86. Theflanges 78 and 84 are received within and are welded to the middle formsection 44, and again optional screws 88 are utilized to further securethe two form sections.

Because of the welded construction throughout, it is seen that there areno breaks or openings in the inner form 10. Thus, said form iscompletely leakproof and watertight,

The outer form 12 consists of a lower section 90 and an upper section92, the lower secton 90 comprising planar and walls 94 and 96, andsidewalls 98 and 100, respectively, the sidewalls 98 and 100 havingenlargements 102 on their opposite ends each containing a groove 104 forreceiving the vertical side edge of one of the end walls 94 and 96. Theend walls 94 and 96 are inserted into the grooves 104, and are welded inplace to form a watertight joint.

The outer form upper section 92 comprises end walls 106 and 108 andsidewalls 110 and 112, respectively, and has a length and widthidentical to that of the lower section 90. The outer bottom edges of thewalls 106, 108, 110 and 112 have downwardly directed flanges 114thereon, which receive the upper end of the lower section 90 and whichare welded thereto. The opposite ends of the sidewalls and 112 haveenlargements 116 thereon containing grooves 118, which receive thevertical edges of the end wall panels 106 and 108, the latter beingwelded in place. Optional screws 120 are also utilized to securetogether the two sections 90 and 92.

The overall height of the outer form 12, which is constructed to bewatertight, is the same as that of the inner form 10, and the two formsare assembled concentrically to define a uniform space of several incheswidth therebetween for receiving concrete. The forms 10 and 12 are heldin concentric relationship by a plurality of spacer dowel assemblies122, the details of one such assembly being shown in FIG. 7.

Referring to FIG. 7, the dowel assembly 122 includesa cylindrical body124 of plastic having reduced diameter end,

portions 126. Plastic washers 128 are received on the end portions 126and are welded to the dowel body 124, and the inner and outer form walls50 and 98, respectively, have holes 130 and 132 therein of a diameter tosnugly receive said end portions. The end portions 126 are inserted intothe holes 130 and 132, and the washers 128 are then welded to thesidewalls 50 and 98. The result is a watertight assembly, the dowelassemblies 122 all cooperating to hold the inner and outer forms 10 and12 in a fixed concentric relationship, and also serving to anchor theforms to the concrete 8. A total of 18 dowel assemblies 122 is shown inthe drawings; obviously, more or fewer can be employed, as desired andas are proved necessary for a given size vault.

In use, after the grave 4 has been dug, the concentrically arrangedinner and outer forms 10 and 12 are lowered therein, with the bottomwall 26 of the inner form 10 and the bottom edge of the outer form 12resting on a plurality of parallel, spaced, vertically disposed spacerbars 134. The bars 134 are made of plastic and can be welded to theundersurface of the bottom wall 26, and each has a plurality of largeholes 136 therethrough for the flow of concrete. The earth of the grave4 therethrough provides a form around the periphery of the spacer bars134.

The forms 10 and 12 can be fabricated and assemblied in concentricrelationship either at the factory, or at the grave site. Thus, theversatility of the invention is increased.

With the forms 10 and 12 in place, concrete mix is poured into the spacetherebetween to form the unitary concrete vault body 8. The concrete mixhas added thereto a waterproofing compound, such as that knowncommercially as Berylex, which reacts with the concrete to provide awater-impervious finished product when the concrete has set and cured.Thus, the watertightness of the burial or casket chambers 20, 22 and 24in the vault is not only assured by the use of the inner and outerplastic forms 10 and 12, but also by the concrete body 8.

Concrete burial vaults have been known to shift their position in theearth over a period of time, often producing an unsightly appearance andrequiring expensive repair work to reset them. It has been found that amajor cause for this shifting can be the accumulation of ground waterunder pressure beneath the vault, and the present invention includesmeans to relieve this pressure and thus alleviate vault shifts from thiscause.

Referring again to FIGS. 1-11, the exterior of each of the inner formend walls 32, 46, 70, 34, 48 and 72 has the base leg of an L-shapedplastic bracket 138 welded thereto, the projecting leg 140 of eachbracket lying in a horizontal plane, and the brackets 138 on each end ofthe inner form 10 being in vertical alignment. The bracket legs 140 eachhave a hole 142 therethrough, the holes 142 at each end of the innerform 10 being in alignment and receiving a pressure relief tube 144. Thepressure relief tubes 144 are secured to the brackets I38, and are of alength so that the lower ends 146 thereof extend below the bottom wall148 of the vault body 8, and so that the upper ends 150 thereof projectsubstantially above the flat top face 152 of the vault body 8,

The pressure relief tubes 144 function to relieve to atmosphere anyground water or other ground pressures that accumulate beneath the vault2. While the tubes 144 are shown embedded within the vault body 8 inFIGS. 1-11, they can optionally be located on the exterior of the outerform 12, as will be described in connection with another embodiment ofthe invention.

After the vault body 0 has been cast in situ and has cured, it is readyfor use. A casket is first placed in the lower casket chamber 20, afterwhich said chamber is closed and sealed by a reinforced rectangularplastic sheet 154 of substantial thickness. Secured by welding to thebottom surface of the sheet 154 at spaced intervals are pairs ofaligned, boxlike reinforcing ribs 156. The ribs extend transversely ofthe sheet 154 and each aligned pair has an overall length about the sameas the distance measured between the opposed flanges 62. Each rib 156include a pair of spaced, parallel, right triangular sidewalls 158, thebase of the triangle being disposed near the outer edges of the sheet154, and the hypotenuse tapering to the center of the sheet. Thesidewalls 158 are boxed in by a plate 160, the result being that eachrib 156 constitutes a structural cantilever-type brace supporting theplastic sheet 154.

The sheet 154 is installed with the peripheral edges thereof resting onthe shoulders 56 and 60, said peripheral edges being welded to theshoulders over the entire length thereof. Thus, when the sheet 154 isinstalled, the casket chamber 20 is completely sealed and watertight,having been rendered watertight first by the inner plastic liner and theplastic sheet 154, and secondly by the waterproofed concrete vault body8 and, to the extent that it covers the exterior of the vault body 8, bythe external plastic form 32.

After scaling of the casket chamber 20, the reinforced plastic sheet 154functions as a shelf to support a casket within the chamber 22. if thechamber 22 is not to be used immediately, the cover slabs 14, 16 and 10are installed to close the burial vault 2.

The cover slab 14 is constructed of concrete having reinforcing rods 162embedded therein, and has a length slightly greater than the distancemeasured between the exterior of the sidewalls of the outer form 12. Theslab 14 has the general cross section of an inverted T, the lower halfof the vertical side edges 164 thereof having rectangular flanges 166formed thereon. Each flange 166 includes a flat horizontal top surface168 and a flat vertical side surface 170, joined by an angled flatsurface 172. The cover slab 14 is secured to the vault body 8 by fourbolts 174, the bolts being passed through bores 176 in the slab andbeing threaded into inserts (not shown) embedded in the top surface 152of the vault body. The upper end of each bore 176 has a recess 178 toreceive the head of the bolt 174, said recess having a heightsubstantially greater than the height of the bolt head, and being sealedby a disk 180 of neoprene or other suitable resilient sealing materialpressed therein on top of the bolt head; The cover slab 14 also has twocentrally located, threaded inserts 182 embedded therein, into whicheyebolts for use in lifting the slab can be threaded.

The end cover slab 16 has a length corresponding to that of the slab 14,and is also constructed of reinforced concrete. it is secured inposition by six bolts 1134, the head of each bolt being received in arecess 186 closed by a resilient sealing disk 188. The end slab 18 is oflike construction, and is secured in place by four bolts 190 havingtheir heads received in recesses 192, the recesses 192 being sealed byresilient disks 193. Both of the cover slabs 16 and 18 have inserts 182embedded therein to receive a lifting eyebolt 1E, and each slab has abore 194 therethrough for reception of the upper end 150 of the pressurerelief tube 144, a resilient scaling sleeve 196 of neoprene or someother suitable material being disposed in each of the bores 194 to sealabout the relief tubes 144.

The inner face of each end slab 16 and 18 has a rectangular flange 198thereon, designed to mate with the flanges 166. The flanges 198 includea flat bottom surface or face 200 and a flat vertical surface 202,connected by a flat angled surface 204. Received between each set offlanges 106 and 198, and running the full length thereof, is a Z-shapedresilient seal 206,

the opposite legs of which are engaged and compressed by the flat angledsurfaces 172 and 204, and the body of which is engaged and compressed bythe flat horizontal surfaces 160 and 200.

For installations of the cover slabs 14, 16 and 10 up until the vault 2is finally filled and closed, a normal rectangular gasket or seal (notshown) is placed on the surface 152, to complete the sealing of thevault. One of the cover slabs, in the drawings the slab 10, usually hasa headstone 20:0 mounted thereon in a recess 210, although the use ofsuch a stone and its placement is a matter of choice.

When it is desired to place a casket in the second casket chamber 22,the slab covers 14, 16 and 10 are removed, and the casket is lowered torest on the reinforced sheet 154. Another reinforced sheet 212, havingreinforcing ribs 214 on the undersurface thereof, is then rested on andwelded to the shoulders 06 and 00, which completely seals the chamber22. The slabs 14, 16 and 10 can then be replaced until the time forusing the upper casket chamber 24 occurs, at which time they are againremoved.

After a casket has been placed in the upper casket chamber 24, a plasticsheet 216 is placed on the vault body to rest on the surface 132, saidsheet having holes therethrough for passage of the bolts 174, and 190,and the pipes 144 The sheet 216 is welded to the top edge of the innerform 10, which thus seals the chamber 24, and the slab covers 14, 16 and10 are then replaced, the portion of the sheet 216 lying. on the surface132 serving as a gasket.

it is obvious that a horizontal vault containing nearly any desiredplurality of casket chambers can be constructed according to theinvention. The inner and outer plastic forms 10 and 12 are locked inplace by the spacer assemblies 122, and the screws 42, 66, and 00, andfunction with the plastic sheets 154, 06 and 216 to make each chamberfully watertight, and totally separate from the other chambers. Thus, amultiple-chamber horizontal vault can be used for one family or forunrelated persons, and with the vertical stacking feature in a singlegrave site provides efficient use of expensive ceme tery land.

The concepts of the invention, however, are also adaptable for in situconstruction of a single casket vault, and such is shown at 300 in FIGS.12-15. The vault 300 is made utilizing inner and outer plastic molds 302and 304, respectively, the inner mold 302 including planar end walls 306and planar sidewalls 300 welded at their mating vertical edges, andWelded to the upstanding integral flange 310 formed on a plastic bottomwall 312, optional screws 314 being utilized to further connect theflange 310 to its associated walls.

The outer form 304 comprises planar end walls 316 connected by weldingto planar sidewalls 310, and has the same height as the inner form. Theinner and outer forms 302 and 304 are mounted in concentric relationshipby spacer assemblies 320 identical to the assemblies 122, and rest onperforated strips 322 placed on the bottom earth wall 324 of a grave326. Pressure relief tubes 320, corresponding to the tubes 144, aresecured by brackets 330 to the end walls 306, and the space between theinner and outer forms 302 and 304 is filled with concrete, with Berglexor the like added thereto, to form the vault body 332.

After a casket has been placed in the vault body 332, a plastic sheet334 is placed thereon and welded to the top edges of the inner formwalls 308 and 306 to completely seal the casket chamber. Theinstallation is then completed by installing cover slabs 14, 16 and 10,identical to the same slabs shown in FIGS. 1-11.

The present concept can also be employed to construct a verticalmultiple-casket burial vault, such being shown at 400 in FIGS. 16 and17. In said FIGS. an outer, rectangular form 402 is constructed like theouter form 12 from sidewalls 404 and end walls 406, the former havingenlargements 408 therein provided with slots 410 to receive the lateraledges of the end walls 406, the entire assembly being welded together.The outer form 402 is placed in a grave 412 to rest on the bottom wall414 thereof, and a plurality of perforated plastic bars 416 are weldedto extend between the form end walls 406.

Disposed to rest on the bars 416 (which correspond to the bars 134 and322) are three plastic inner forms 418, each comprising a frustoconicalbody 420 shaped to receive a frustoconical casket therein, and a bottomwall 422, the inner forms 418 being watertight. The spaces between theinner and outer forms 402 and 418 are then filled with concretecontaining Berylex, or the like, to form a concrete vault body 423.

The three casket chambers are individually closed by rectangularconcrete slab covers 424, 426 and 428, secured by bolts 430 threadedinto inserts embedded in the top surface 432 of the vault body 423, thebolt heads being received in recesses 434 closed by resilient disks 436.Each cover has a headstone 438 mounted thereon, and has inserts 440embedded therein to receive a lifting eyebolt.

After a casket has been placed in one of the casket chambers, arectangular plastic sheet 442 is placed over the mouth of the inner form418 and welded thereto, and the appropriate cover 424, 426 or 428 isthen installed. Again, the result is a watertight, plastic-lined casketchamber. When all the covers 424, 426 and 428 are installed, the jointstherebetween are filled with mortar 443.

it was mentioned hereinabove that the pressure relief tube of theinvention could be embedded in the vault body, or that it could besecured to the outer form. In FlGS. 16 and 17 the latter construction isshown, and pressure relief tubes 444 are welded to the exterior surfacesof the end walls 406.

While the inner and outer plastic forms of FIGS. 1-14, and the outerform of FIGS. 16 and 17 have been shown as being made up from separatepieces, which makes for ease of transport, it would also be possible tomold them as one-piece units. Alternatively, the walls defining eachcasket chamber could be molded in one piece as subunits, and these couldthen be secured together to form a vault of any desired height. All ofthese constructions forthe forms are within the concept of theinvention.

Obviously, many other modifications and variations of the presentinvention are possible.

lclaim:

l. A waterproof burial vault constructed in situ, comprising: at leastone watertight inner plastic form having a bottom wall and open at thetop; an outer plastic form of larger size than said inner plastic formand disposed in spaced relationship thereabout, said inner and outerplastic forms being adapted to be placed within a dug grave; a pluralityof spacer bars beneath at least said inner form for supporting the samein an elevated position above the bottom of said grave, said spacer barshaving openings therein for the flow of wet concrete around said bars,and the upper edges of said inner and outer plastic forms being spacedso that concrete can be poured between said forms; a unitary concretevault body cast in situ between said inner and outer forms and includinga bottom wall within which said spacer bars are embedded, whereby saidforms and said concrete vault body constitute a unified burial vaultbody open at the top, said inner form defining at least one casketreceiving chamber; a sheet of plastic adapted to be secured in awatertight manner to the upper edge of each said inner plastic formcompletely around the periphery thereof to seal said chamber; and covermeans placed on said concrete vault body to complete said burial vault.

2. A waterproof burial vault as recited in claim 1, wherein the concreteof said vault body contains a waterproofing compound to render the sameimpervious to the passage of water.

3. A waterproof burial vault as recited in claim 1, including aplurality of separate inner forms arranged in side-byside spacedrelationship, each inner form defining a single casket receiving chamberand resting on a plurality of said spacer bars, and said cover meansincluding a separate cover for each casket chamber.

4. A waterproof burial vault as recited in claim 1, wherein said outerform comprises: a pair of end walls and a pair of sidewalls, one of saidpair of sidewalls and end walls being planar, and the other thereofhaving groove defining means on the vertical edges thereof, the verticaledges of said planar walls being received within said grooves and beingsecured in a watertight manner to said other walls. I

5. A waterproof burial vault as recited in claim 1, including at leastone pressure relief tube mounted to extend from beneath said vault bodybottom wall to the top of said burial vault, said relief tube being openat both ends for relieving pressure accumulations beneath and outside ofsaid burial vault.

6. A waterproof burial vault as recited in claim 5, wherein saidpressure relief tube is embedded within said concrete vault body.

7. A waterproof burial vault as recited in claim 5, wherein saidpressure relief tube is secured to the exterior of said outer plasticform.

8. A waterproof burial vault as recited in claim 1, wherein the topsurface of said unified burial vault body is planar, and wherein saidsurface has a plurality of spaced inserts embedded therein, said covermeans including; at least two cover slabs disposed to rest side by sideon said planar vault body top surface, the confronting sides of saidslabs having overlapped flanges thereon, and said slabs having borestherethrough aligned with said embedded inserts; a resilient Z-shapedseal disposed between said overlapped flanges; seal means between saidslabs and the top planar surface of said vault body; and a plurality ofbolts received in said bores and threaded into said embedded inserts forsecuring said cover slabs in place.

9. A waterproof burial vault as recited in claim 8, wherein said boresare recessed to receive the heads of said bolts, said recesses having adepth substantially greater than the height of said bolt heads; andfurther including disks of resilient material received within saidrecesses on top of said bolt heads, said disks sealing said boresagainst the passage of liquid.

10. A waterproof burial vault as recited in claim 8, wherein said sheetof plastic secured to the open end of said inner plastic form extendsoutwardly over said top planar surface of said vault body, saidoutwardly extending portion of said sheet serving as said seal meansbetween said cover slabs and the vault body.

11. A waterproof burial vault as recited in claim 1, wherein in additionto said bottom wall said inner form includes a pair of end walls and apair of sidewalls, and wherein said outer form includes a pair of endwalls and a pair of sidewalls, said burial vault further including; aplurality of spacer means interconnecting walls of said outer form withtheir confronting inner form walls, said spacer means serving both tohold said inner and outer forms in concentric relationship during thepouring of said concrete vault body, and to anchor said inner and outerforms to said vault body.

12. A waterproof burial vault as recited in claim 11, wherein each ofsaid spacer means comprises: an elongated body disposed between saidinner and outer forms and having a reduced diameter portion on each endthereof; and a washer received on each reduced diameter end portion andsecured to said elongated body, the reduced diameter end portions ofsaid body being received in confronting openings in the opposed walls ofsaid inner and outer forms, and said washers abutting against and beingsecured to said opposed walls.

13. A waterproof burial vault as recited in claim 11, wherein said innerform contains a plurality of casket-receiving chambers disposedvertically one above another, said sidewalls and said end walls of saidinner form having inwardly extending shoulder means thereon at thejuncture of each chamber with the chamber thereabove, and said burialvault further including; a reinforced sheet of plastic disposed to reston each said shoulder means and adapted to be sealed in a watertightmanner to the sidewalls and the end walls of said inner form for sealingthe casket chamber therebelow, each said reinforced sheet furtherserving as a shelf to support a casket received in the casket chamberimmediately thereabove.

14. A waterproof burial vault as recited in claim 13, wherein each saidshoulder'means is continuous and presents a planar upper surface forreceiving and supporting the edges of said reinforced sheet.

35. A waterproof burial vault as recited in claim 13, wherein saidreinforced sheet comprises: a planar sheet of plastic of substantialthickness; and a plurality of pairs of aligned cantilever type bonedbeams secured to the undersurface of said planar sheet.

16. A waterproof burial vault as recited in claim 13, wherein said innerform comprises: a rectangular bottom wall having an upstanding flangeextending about the periphery thereof; a pair of planar end walls and apair of planar sidewalls defining the lowermost of said casket chambers,the vertical edges of said planar sidewalls and end walls being securedtogether in a watertight manner, and the bottom edges of said planarsidewalls and end walls being secured in a watertight manner to saidupstanding flange; and a pair of sidewalls and end walls for each uppercasket chamber, the vertical edges of said upper chamber side and endwalls being secured together in a watertight manner, the top ends ofsaid upper chamber side and end walls being planar, and the bottom edgesof said upper chamber side and end walls having inwardly and downwardlyextending flanges thereon, the upper surfaces of said flanges definingsaid shoulder means, and said flanges being received within and securedin a watertight'manner to the end walls and sidewalls defining thecasket chamber therebelow.

117. A waterproof burial vault as recited in claim 16, further includinga plurality of elongated fasteners extending through lid said upstandingflange and said downwardly extending flanges,

vault, comprising the steps of: excavating a grave in the earth 7 to adepth so that the bottom thereof lie at the level at which the bottom ofthe vault is to be positioned; positioning within said grave an outerplastic form having disposed therewithin at least one inner plastic formof watertight construction having a bottom wall and being open at thetop, said inner plastic form defining at least one casket receivingchamber and being spaced from said inner form, said inner and outerforms being held above the bottom of said grave by spacer means disposedtherebetween, and the top edge of said inner and outer forms beingspaced for pouring concrete therebetween; pouring concrete mix into thespace defined between said inner and outer plastic forms, and betweensaid forms and the walls of said grave at the bottom thereof; curingsaid concrete with said plastic forms in place, whereby to produce aunified vault body containing at least one waterproof casket receivingchamber; securing a plastic sheet across the open upper end of saidinner plastic form in a watertight manner; and mounting cover means tothe upper end of said vault body, over said plastic sheet.

H9. The method as recited in claim i8, including additionally adding awaterproofing compound to said concrete mix before the pouring thereofv

1. A waterproof burial vault constructed in situ, comprising: at leastone watertight inner plastic form having a bottom wall and open at thetop; an outer plastic form of larger size than said inner plastic formand disposed in spaced relationship thereabout, said inner and outerplastic forms being adapted to be placed within a dug grave; a pluralityof spacer bars beneath at least said inner form for supporting the samein an elevated position above the bottom of said grave, said spacer barshaving openings therein for the flow of wet concrete around said bars,and the upper edges of said inner and outer plastic forms being spacedso that concrete can be poured between said forms; a unitary concretevault body cast in situ between said inner and outer forms and includinga bottom wall within which said spacer bars are embedded, whereby saidforms and said concrete vault body constitute a unified burial vaultbody open at the top, said inner form defining at least one casketreceiving chamber; a sheet of plastic adapted to be secured in awatertight manner to the upper edge of each said inner plastic formcompletely around the periphery thereof to seal said chamber; and covermeans placed on said concrete vault body to complete said burial vault.2. A waterproof burial vault as recited in claim 1, wherein the concreteof said vault body contains a waterproofing compound to render the sameimpervious to the passage of water.
 3. A waterproof burial vault asrecited in claim 1, including a plurality of separate inner formsarranged in side-by-side spaced relationship, each inner form defining asingle casket receiving chamber and resting on a plurality of saidspacer bars, and said cover means including a separate cover for eachcasket chamber.
 4. A waterproof burial vault as recited in claim 1,wherein said outer form comprises: a pair of end walls and a pair ofsidewalls, one of said pair of sidewalls and end walls being planar, andthe other thereof having groove defining means on the vertical edgesthereof, the vertical edges of said planar walls being received withinsaid grooves and being secured in a watertight manner to said otherwalls.
 5. A waterproof burial vault as recited in claim 1, including atleast one pressure relief tube mounted to extend from beneath said vaultbody bottom wall to the top of said burial vault, said relief tube beingopen at both ends for relieving pressure accumulations beneath andoutside of said burial vault.
 6. A waterproof burial vault as recited inclaim 5, wherein said pressure relief tube is embedded within saidconcrete vault body.
 7. A waterproof burial vault as recited in claim 5,wherein said pressure relief tube is secured to the exterior of saidouter plastic form.
 8. A waterproof burial vault as recited in claim 1,wherein the top surface of said unified burial vault body is planar, andwherein said surface has a plurality of spaced inserts embedded therein,said cover means including; at least two cover slabs disposed to restside by side on said planar vault body top surface, the confrontingsides of said slabs having overlapped flanges thereon, and said slabshaving bores therethrough aligned with said embedded inserts; aresilient Z-shaped seal disposed between said overlapped flanges; sealmeans between said slabs and the top planar surface of said vault body;and a plurality of bolts received in said bores and threaded into saidembedded inserts for securing said cover slabs in place.
 9. A waterproofburial vault as recited in claim 8, wherein said bores are recessed toreceive the heads of said bolts, said recesses having a depthsubstantially greater than the height of said bolt heads; and furtherincluding disks of resilient maTerial received within said recesses ontop of said bolt heads, said disks sealing said bores against thepassage of liquid.
 10. A waterproof burial vault as recited in claim 8,wherein said sheet of plastic secured to the open end of said innerplastic form extends outwardly over said top planar surface of saidvault body, said outwardly extending portion of said sheet serving assaid seal means between said cover slabs and the vault body.
 11. Awaterproof burial vault as recited in claim 1, wherein in addition tosaid bottom wall said inner form includes a pair of end walls and a pairof sidewalls, and wherein said outer form includes a pair of end wallsand a pair of sidewalls, said burial vault further including; aplurality of spacer means interconnecting walls of said outer form withtheir confronting inner form walls, said spacer means serving both tohold said inner and outer forms in concentric relationship during thepouring of said concrete vault body, and to anchor said inner and outerforms to said vault body.
 12. A waterproof burial vault as recited inclaim 11, wherein each of said spacer means comprises: an elongated bodydisposed between said inner and outer forms and having a reduceddiameter portion on each end thereof; and a washer received on eachreduced diameter end portion and secured to said elongated body, thereduced diameter end portions of said body being received in confrontingopenings in the opposed walls of said inner and outer forms, and saidwashers abutting against and being secured to said opposed walls.
 13. Awaterproof burial vault as recited in claim 11, wherein said inner formcontains a plurality of casket-receiving chambers disposed verticallyone above another, said sidewalls and said end walls of said inner formhaving inwardly extending shoulder means thereon at the juncture of eachchamber with the chamber thereabove, and said burial vault furtherincluding; a reinforced sheet of plastic disposed to rest on each saidshoulder means and adapted to be sealed in a watertight manner to thesidewalls and the end walls of said inner form for sealing the casketchamber therebelow, each said reinforced sheet further serving as ashelf to support a casket received in the casket chamber immediatelythereabove.
 14. A waterproof burial vault as recited in claim 13,wherein each said shoulder means is continuous and presents a planarupper surface for receiving and supporting the edges of said reinforcedsheet.
 16. A waterproof burial vault as recited in claim 13, whereinsaid inner form comprises: a rectangular bottom wall having anupstanding flange extending about the periphery thereof; a pair ofplanar end walls and a pair of planar sidewalls defining the lowermostof said casket chambers, the vertical edges of said planar sidewalls andend walls being secured together in a watertight manner, and the bottomedges of said planar sidewalls and end walls being secured in awatertight manner to said upstanding flange; and a pair of sidewalls andend walls for each upper casket chamber, the vertical edges of saidupper chamber side and end walls being secured together in a watertightmanner, the top ends of said upper chamber side and end walls beingplanar, and the bottom edges of said upper chamber side and end wallshaving inwardly and downwardly extending flanges thereon, the uppersurfaces of said flanges defining said shoulder means, and said flangesbeing received within and secured in a watertight manner to the endwalls and sidewalls defining the casket chamber therebelow.
 17. Awaterproof burial vault as recited in claim 16, further including aplurality of elongated fasteners extending through said upstandingflange and said downwardly extending flanges, and projectingsubstantially beyond the outer surface of said inner form, the extendingportions of said fasteners being embedded in said concrete vault body tofurther secure said inner form thereto.
 18. The method for constructingin situ a waterproof burial vault, comprising the steps of: excavating agrave in the earth to a depth so that the bottom thereof lie at thelevel at which the bottom of the vault is to be positioned; positioningwithin said grave an outer plastic form having disposed therewithin atleast one inner plastic form of watertight construction having a bottomwall and being open at the top, said inner plastic form defining atleast one casket receiving chamber and being spaced from said innerform, said inner and outer forms being held above the bottom of saidgrave by spacer means disposed therebetween, and the top edge of saidinner and outer forms being spaced for pouring concrete therebetween;pouring concrete mix into the space defined between said inner and outerplastic forms, and between said forms and the walls of said grave at thebottom thereof; curing said concrete with said plastic forms in place,whereby to produce a unified vault body containing at least onewaterproof casket receiving chamber; securing a plastic sheet across theopen upper end of said inner plastic form in a watertight manner; andmounting cover means to the upper end of said vault body, over saidplastic sheet.
 19. The method as recited in claim 18, includingadditionally adding a waterproofing compound to said concrete mix beforethe pouring thereof.
 35. A waterproof burial vault as recited in claim13, wherein said reinforced sheet comprises: a planar sheet of plasticof substantial thickness; and a plurality of pairs of aligned cantilevertype boxed beams secured to the undersurface of said planar sheet.